Electrical connectors



May 14, 1963 F. M. RADDIN ELECTRICAL CONNECTORS Original Filed Dec. 13, 1956 IlIlIllllllllllllllllllll FIG.2

INVENTOR. FRANKLIN M. RADDIN ATTORNEY United States Patent 3,090,026 ELECTRICAL CONNECTORS Franklin M. Raddin, Morristown, NJ assignor to Monroe Calculating Machine Company, Orange, NJ a corpcration of Delaware Original application Dec. 13, 1956, Ser. No. 628,034, now Patent No. 2,956,258, dated Oct. 11, 1960. Divided and this application Sept. 30, 1960, Ser. No. 59,537

6 Claims. (Cl. 339-17) This invention, which is a division of copending patent application 628,034, filed December 13, 1956, now Patent 2,956,258 dated October 11, 1960, by Franklin Riddin, relates to electrical connectors for printed circuit cards or the like.

It well known that printed circuit cards provide a number of advantages when used in electronic apparatus. Such cards are especially suited to mass production and make possible a reduction in the size of electronic apparatus. They also provide a modular type of construction in electronic equipments that simplifies the maintenance problem by permitting a quick substitution of small units which become defective.

To provide for easy replacement, the printed circuit cards normally include multicontact plugs which enter into sockets in a chassis or inter-connection unit. The making of soldered connections to the ends of the plug adds to the cost of construction and such plugs have a number of disadvantages as a means for making connections to printed circuit cards, especially when the cards are miniaturized.

Theplugs require an appreciable mechanical force on each pin to insure a reliable contact resistant to corrosion, vibration, and-shock. As many contacts are normally required, the force necessary for insertion and removal of a card is considerable. Equipments using printed circuit cards are normally compact so that it is frequently diflicult to apply an appreciable force to remove and insert the cards.

In any event, the plugs limit the degree of miniaturization which can be obtained. The card must be large enough to withstand the forces applied to it for insertion and removal. The pin size and spacing necessary for the plug is another limiting factor on the size of the card.

The apparatus of the instant invention provides a means for making reliable connections directly to the printed terminals along the edges of printed circuit cards. The spacing of the printed terminals may be the same as the spacing of other printed conductors. Substantially zero force is required to insert and remove the cards so that they need to be only strong enough to support the printed circuitry and other circuit components.

In the apparatus of the instant invention, a fluid pressure is applied uniformly along rows of mating contacts to hold them together with suflicient force to insure connections resistant to corrosion, vibration, and shock. At least one of the cards or other member supporting sets of contacts is flexible and the fluid pressure means is conformable in shape so that a substantially uniform pressure will be applied to each pair of mating contacts despite small dimensional variations in the contacts or their supporting members. The fluid pressure is removed to allow insertion and removal without wear and undesirable mechanical stress.

An object of the invention is an improved means of making connections to printed circuit cards.

A further object of the invention is apparatus for making connections directly to printed terminals on printed circuit cards wherein a uniform contact pressure is maintained with each terminal.

A still further object of this invention is apparatus for making connections to printed circuit cards from which 2 the cards may be inserted and removed with the application of substantially zero force.

Other objects and advantages together with a fuller understanding of the invent-ion, will be had by referring to the following description and claims taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a fragmentary portion of the invention.

FIG. 2 is a plan View of a horizontal section of the embodiment of FIG. 1 taken along the line 6-6.

FIG. 3 is an elevation view of a vertical section of the fragmentary portion of the embodiment of FIG. 5 taken along the ilne 7-7.

FIGURES 1, 2, and 3 show an arrangement for connecting a number of printed circuit cards 13a to an interconnection panel 22 which may be of the printed circuit type. This arrangement is useful in many types of electronic apparatus where a number of printed circuit cards are to be connected to a single chassis or other type of inter-connection unit.

Flat rectangular case 23 has a plurality of vertical slots 32 into which cards 13o can be inserted and a horizontal slot 34 adapted to receive panel 22. Flexible bag 24 is located inside case 23 and has fingers 24a extending between the several ventical slots. Tube 25 is an extension of bag 24 and runs through a hole in case 23 to valve 26. Tube 25 provides a fluid communicating passage between valve 26 and bag 24. Valve 26 may connect tube 25 either to atmospheric pressure through a vent outlet or to pressure source 27.

Insulting members 28 having an L-shaped cross section are movably supported along each vertical slot with one side of the L parallel to the veritca-l slot and the other parallel to the horizontal slot. The movable support fior members 28 is provided by rubber bushings 30 on pins 29 which project from case 23 at each end of the vertical slots. Each member 28 has a plurality of printed conductors 17" that each have a portion on the sides adjacent to the vertical and horizontal slots. The conductors 17" on each member 28 are in mating relation with the conductors 17 on cards 13a and panel 22.

With cards 13a! and panel 22 in their respective slots, pressure is applied to bag 24 by turning valve 26 to connect tub-e 25 to the pressure source 27. Expansion of bag 24 forces members 28 against their respective cards 13a and against panel 22. Conductors 17" on members 28 then make contact with conductor 17 on cards 13a and panel 22 and provide the desired interconnections between cards 13a and panel 22. Members 28 are sufiicient- 1y flexible so that each pair of mating conductors 17 will be held together with substantially the same pressure.

In the embodiment shown, bag 24 and pressure source 27 are filled with a pneumatic fluid, such as air. When a card 13:11 or panel 22 is to be removed, the pressure exerted by bag 24 is released by turning valve 26 to connect tube 25 to the vent. When new cards 13w or panels 22 have been inserted, pressure is again applied by turning valve 26 to again connect tube 25 to pressure source 27. Pressure source 27 may be of any suitable type such as a pump and pressure tank or accumulator.

It will be recognized that bag 24 could also be filled with an incompressible hydraulic fluid and pressure applied against the bag through a plate and screw arrangement. It will further be recognized that various other arrangements could also be used for obtaining fluid pressure in the several embodiments of the invention other than those shown. For example, a type mechanism positioned by a lever could be used instead of a screw to move a plate against the bag. Such a mechanism would permit quick application and removal of pressure but would require an additional adjusting means to obtain the desired pressure in the event of changes in dimensions of the chamber in which the bag is located or of the cards and connectors used.

While the invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of construction wherein a combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. An electrical connector comprising a housing having two slots and a fluid filled chamber with flexible wall sections along a side of each of said slots, means for controlling the fluid pressure in said chamber to move said flexible wall sections with respect to said slots, a plurality of first electrical conductors each having a portion mounted on each of said flexible wall sections, insulating members positioned in said slots, and a plurality of second electrical conductors mounted on each of said insulating members in mating relation with the portions of said first electrical conductors on the adjacent one of said flexible wall sections.

2. The combination according to claim 1 wherein said housing has a plurality of first slots and a second slot intersecting said first slots and wherein each of said first electrical connectors has a portion mounted on a flexible wall section along one of said first slots and another portion on a flexible wall section along said second slot.

3. An electrical connector comprising a housing having two slots and a chamber with an opening along each of said slots, a fluid filled bag mounted in said chamber and having flexible sections, means for controlling the fluid electrical connectors on said card members in mating relation with said first electrical conductors.

4. The combination according to claim 3 wherein said housing has a plurality of first slots and a second slot in tersecting said first slots and wherein there are a plurality of flexible insulating members yieldably mounted on said housing each having a section along the side of one of said first slots and a section along the side of said second slot.

5. An electrical connector comprising a housing having a substantially linear series of first slots, an intersecting slot substantially perpendicular to said first slots, a closed flexible bag filled with a substantially incompressible fluid mounted in said housing with a first wall thereof coextensive with one side of at least one of the said first slots and having a second Wall coextensive with one side of the intersecting slot, conductor carrying members adapted to fit in said slots, one of said members having portions thereof adjacent both said first and second walls of said bag and having conductors thereon which abut conductors of other members, and means for exerting a force on said bag whereby said abutting conductors are secured by movement of the walls of said bag.

6. The combination of claim 5 wherein said conductor carrying members are cards of insulating material having conducting material selectively printed thereon and said one of said members has associated therewith an L-shaped member of insulating material having conducting material selectively printed on the outer portion of the legs thereof, said L-shaped member being moveably supported with its legs respectively adjacent said first and second slots.

References Cited in the file of this patent UNITED STATES PATENTS 2,456,902 Treuthart Dec. 21, 1948 2,685,071 McCreary July 27, 1954 2,757,225 Dunn July 31, 1956 2,827,312 Spencer Mar. 18, 1958 2,832,942 French Apr. 29, 1958 2,852,463 Gutzmer Sept. 16, 1958 

1. AN ELECTRICAL CONNECTOR COMPRISING A HOUSING HAVING TWO SLOTS AND A FLUID FILLED CHAMBER WITH FLEXIBLE WALL SECTIONS ALONG A SIDE OF EACH OF SAID SLOTS, MEANS FOR CONTROLLING THE FLUID PRESSURE IN SAID CHAMBER TO MOVE SAID FLEXIBLE WALL SECTIONS WITH RESPECT TO SAID SLOTS, A PLURALITY OF FIRST ELECTRICAL CONDUCTORS EACH HAVING A PORTION MOUNTED ON EACH OF SAID FLEXIBLE WALL SECTIONS, INSULATING 